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1.
Many species of gazelles (Gazella spp.) are nowadays threatened by hunting, poaching, habitat loss and habitat deterioration. Conservation efforts for this group not only face the problem of maintaining remnant populations, but often natural populations have been extirpated from the wild. In some cases, though, captive breeding programs exist that might provide a valuable source for future reintroductions. A major problem in this context is that phylogeographic relationships among different (potentially locally adapted) populations, and even basic phylogenetic relationships between species, are poorly understood, thus hampering the assignment of management units, breeding groups or stocks for reintroduction projects. Our present study focused on Dorcas gazelles (G. dorcas and G. saudiya) from the species’ entire distribution range, with samples originating from western Saharan Africa into Saudi Arabia. In stark contrast to previous studies reporting on pronounced genetic structure in taxa such as Mountain gazelles (G. gazella), we detected low genetic diversity and no evidence for major phylogenetic lineages when analyzing two mitochondrial genetic markers. Using a coalescent approach we infer a steep population decline that started approximately 25,000 years before present and is still ongoing, which coincides with human activities in Saharan Africa. Our phylogenetic analyses, statistical parsimony network analysis and inferred colonization patterns shed doubt on the validity of various described subspecies of G. dorcas.  相似文献   

2.
Blue sheep, Pseudois nayaur, is endemic to the Tibetan Plateau and the surrounding mountains, which are the highest‐elevation areas in the world. Classical morphological taxonomy suggests that there are two subspecies in genus Pseudois (Bovidae, Artiodactyla), namely Pseudois nayaur nayaur and Pseudois nayaur szechuanensis. However, the validity and geographic characteristics of these subspecies have never been carefully discussed and analyzed. This may be partially because previous studies have mainly focused on the vague taxonomic status of Pseudois schaeferi (dwarf blue sheep). Thus, there is an urgent need to investigate the evolutionary relationship and taxonomy system of this genus. This study enriches a previous dataset by providing a large number of new samples, based on a total of 225 samples covering almost the entire distribution of blue sheep. Molecular data from cytochrome b and the mitochondrial control region sequences were used to reconstruct the phylogeny of this species. The phylogenetic inferences show that vicariance plays an important role in diversification within this genus. In terms of molecular dating results and biogeographic analyses, the striking biogeographic pattern coincides significantly with major geophysical events. Although the results raise doubt about the present recognized distribution range of blue sheep, they have corroborated the validity of the identified subspecies in genus Pseudois. Meanwhile, these results demonstrate that the two geographically distinct populations, the Helan Mountains and Pamir Plateau populations, have been significantly differentiated from the identified subspecies, a finding that challenges the conventional taxonomy of blue sheep.  相似文献   

3.
The classification of the Carassius complex (Cyprinidae) including all-female triploids, called ginbuna in Japanese, is so confused that three sympatric morphs of crucian carp in Lake Kasumigaura are categorized into two different subspecies within a species. We examined them in order to explain the coexistence of more than one subspecies and determine the founder of the triploid lineages in the crucian carp fauna in the lake. Principal component analysis proved that the three sympatric morphs had a morphometric basis distinguishable from each other. Ploidy was determined by flow cytometry which showed triploids in two morphs and diploids in the other morph. Stepwise discriminant analysis using only meristic characteristics could separate the diploids from the triploids. Phylogenetic analysis using mitochondrial DNA inferred two lineages in which one was composed of a triploid morph and the other was a diploid–triploid mixture. Disagreement between the taxonomic status and the phylogenetic status is explicable by assuming that the triploids in the Carassius complex had independent origins leading to the different subspecies. C. auratus langsdorfii appears to show genetic complexities that traditional taxonomic classification can not unravel.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 79 , 351–357.  相似文献   

4.
Aquaticus and Barbareifolius are two subgroups of Senecio aquaticus s. l. (Asteraceae) that have been recognized at various taxonomic levels in European taxonomic literature. In this paper we present the results of morphological studies on S. aquaticus s. l. in order to establish the taxonomic status of these two subgroups. Using multivariate morphometric techniques (discriminant analysis and principal component analysis), we examined the diagnostic potential of 60 macro-morphological characters and studied the delimitation of Aquaticus and Barbareifolius. Seven of the characters studied were included in the discriminant function of the stepwise discriminant analysis and are therefore considered to be the most reliable diagnostic characters of Aquaticus and Barbareifolius. Barbareifolius has, amongst other distinguishing traits, a more divaricate inflorescence than Aquaticus. Because both subgroups are distinct but overlapping clusters in multivariate morphometric space, and because clear differences in their geographical distribution are absent, we recommend the taxonomic status of variety to both groups. Following the rules of nomenclature, Aquaticus and Barbareifolius should therefore be named S. aquaticus Hill var. aquaticus and S. aquaticus Hill var. barbareifolius (Krock.) Wimm. & Grab.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 145 , 489–498.  相似文献   

5.
In Central Europe and Asia Minor Zygaena purpuralis and Z. minos are two sibling species exhibiting a considerable geographic variation in several features. In this study we examine some populations from the Central and Southern Apennines (Italy) by comparing multivariate analyses of individual allozymic multilocus profiles and of individual morphometric profiles of male genitalia in order to assess their genetic and phenetic relationships.
Results indicate that populations of Z. purpuralis in the Apennines behave in rather different ways with respect to the occurrence of gene exchange with other gene pools. No gene flow appears to occur between two geographically close southern populations; however, extensive introgression, revealable at both the allozymic and morphometric level, seems to occur between some purpuralis and minos -like sympatric populations from Abruzzi. Evolutionary relationships among these peninsular Italy populations are discussed with reference to historical factors, that is, the occurrence of multiple Pleistocene refugia, which could have determined different degrees of isolation among gene pools. This situation is rather different from that previously outlined for Central Europe and present results suggest that the Z. purpuralis complex might include more than two biological species.  相似文献   

6.
7.
Chironius is one of the most speciose genera of the South American colubrid snakes. Although the genus represents a well‐known radiation of diurnal racers, its monophyly, affinities with other Neotropical colubrid genera, and intrageneric relationships are open questions. Here, we present a phylogenetic analysis of Chironius based on a data matrix that combines one nuclear (c‐mos) and two mitochondrial (12S and 16S rRNA) genes with 37 morphological characters derived from scutellation, skull, and hemipenial features. Phylogenetic relationships were inferred using maximum parsimony (MP) and maximum likelihood (ML). Our combined morphological and molecular analyses strongly support the monophyly of the genus Chironius and its sister‐group relationship with a clade formed by the genera Dendrophidion and Drymobius. Phylogenetic relationships within the genus Chironius is still controversial, although five clades are retrieved with medium to strong support. © 2014 The Linnean Society of London  相似文献   

8.
Acoustic behaviour was studied in the four species of Alebra Fieber leafhoppers found in Britain, which are morphologically the closest in the genus: A. wahlbergi (Boheman), A. coryli Le Quesne, A. albostriella (Fallen) and A. viridis Rey. One male call, of a diagnostic structure and produced in all behavioural contexts observed, was recorded for each species. No female acoustic signals were identified. Using male call pattern the three species of Alebra coexisting on Castanea sativa Miller in Kastanitsa, southern Greece, were identified as A. wahlbergi, A. albostriella and A. viridis. Individuals of A. viridis from Kastanitsa had more pronounced external pigmentation than those from Cardiff, South Wales. Discriminant and principal component analysis on variables of the male call of A. viridis distinguished the populations from Cardiff and Kastanitsa, but could not differentiate populations from the two British host plants, Quercus petraea and Q. cerris , in Cardiff. The British and Greek populations differed in the covariation as well as the duration of call components.
Castanea sativa was also recognized as a host plant of A. viridis in Cardiff. Individuals collected from C. saliva had external patterning in the same range of variation as that found for individuals from species of Quercus.
Present evidence strongly suggests that divergence in the acoustic species recognition signals of Alebra is occurring among geographic rather than sympatric host plant-associated populations.  相似文献   

9.
Over the last few years, molecular-based assays in the genus Artemia have considerably enriched prior systematic assessments based on morphometry. For the first time, morphometric and 16S rRNA PCR-RFLP analyses on all type-locality bisexual species of the genus have been employed here. Emphasis was put on the Asian species ( Artemia urmiana , A. tibetiana , A. sinica ) where patterns of divergence and reproductive isolation are rather discrete, and especially on A. tibetiana for which recent reports have questioned its specific status. Discriminant analysis of morphometric characters has shown significant differentiation among species. Classification scores were 99.4 and 100% for males and females, respectively. Mitochondrial DNA RFLP patterns have given indications for lower, albeit similar patterns of differentiation compared with those obtained by morphometry. Artemia tibetiana and A. urmiana are mitochondrially indistinguishable which is suggestive of recent ancestry. Our data, in conjunction with past evidence, are supportive of a significant amount of divergence between A. tibetiana and A. sinica . Morphometric and molecular assays can be reciprocally informative provided theory and patterns of speciation are incorporated into systematic assessments.  相似文献   

10.
Recent work on terrestrial isopods has shown that morphospecies can have a high degree of genetic diversity. We conducted a molecular phylogenetic study of Spherillo grossus (Budde‐Lund, 1885), a terrestrial isopod endemic to the east coast of Australia. We sequenced the mitochondrial 16S rDNA gene of 63 specimens from 12 collection localities. From a subset of these specimens, we also sequenced the mitochondrial cytochrome c oxidase subunit I (COI) and nuclear 18S rDNA genes. Deep mitochondrial divergences were found among groups of individuals (with p‐distances up to 15, 14, and 0.7% for 16S, COI, and 18S respectively), a pattern consistent with the hypothesis that gene flow between populations has been influenced by the fragmentation of Australia's mesic environment since the Miocene. We also found evidence of human‐mediated dispersal of S. grossus. Scanning electron and light microscopy of a subset of samples provide preliminary evidence that S. grossus is morphologically homogeneous. Our results mirror those found in studies of oniscid isopods from the Northern Hemisphere. © 2013 The Linnean Society of London  相似文献   

11.
Corylus mandshurica Maxim. & Rupr. 和 C. sieboldiana Blume 在中国和俄罗斯一直被处理为独立的种。本文对来自不同标本室的这两个种的腊叶标本及野外采集的大量叶片进行了形态学分析,以确定形态分化是否足够成为建立种的依据。对采自中国、韩国和日本覆盖两个种分布区的153份标本的18个形态学性状进行了统计,以构建数据矩阵用于主成分分析。结果表明,包含C. sieboldiana 复合体的数据单位(entities)在所有的形态学性状上均呈现出广泛的重叠区域。叶片和果实性状分析结果表明类群间缺乏分异性。基于形态学性状不足以把 C. mandshurica 从C. sieboldiana 中分离出去,并给予种的等级,也就是说这两个类群在形态上没有完全分化,而且它们的分布区也是相连的。 因此,应该把C. mandshurica作为C. sieboldiana 的种下分类群处理。C. sieboldiana在韩国南部和日本的具短总苞的植物常常被处理为独立的种或变种,但实际上应该作为C. sieboldiana 内的变型处理,因为总苞性状高度变异,即使在同一个体上也是如此。  相似文献   

12.
Brown algae of the order Laminariales, commonly referred to as kelps, are the largest and most productive primary producers in the coastal inshore environment. The genus Ecklonia (Lessoniaceae, Phaeophyceae) consists of seven species with four species in the Northern Hemisphere and three in the Southern Hemisphere. It was recently transferred to the family Lessoniaceae based on phylogenetic analyses of nuclear and chloroplastic markers, though the type of the genus was not included and its relationship with allied genera Eckloniopsis and Eisenia remained unresolved. The present study is the first to produce a phylogeny focussed on the genus Ecklonia. It included sequences from nuclear, mitochondrial, and chloroplastic DNA, for most of the distribution range of the three current Southern Hemisphere species (Ecklonia radiata, Ecklonia maxima, and a sample of a putative Ecklonia brevipes specimen), sequences for East Asiatic species (Ecklonia cava, Ecklonia kurome, and Ecklonia stolonifera), as well as the closely related genera Eckloniopsis and Eisenia. Results confirmed E. radiata and E. maxima as two distinct species in South Africa, E. radiata as a single species throughout the Southern Hemisphere (in South Africa, Australia, and New Zealand) and East Asiatic species as a distinct lineage from the Southern Hemisphere clade. Results further pointed out a close sister relationship between Eckloniopsis radicosa and two Eisenia species (including the type species: Eisenia arborea) to the genus Ecklonia suggesting that the genera Eckloniopsis and Eisenia are superfluous.  相似文献   

13.
14.
Vanilla claviculata (W.Wright) Sw. and K barbellata Rchb.f. grow sympatrically in the southwestern part of herto Rico. At three localities in the range of the two species, individuals with flowers that appeared Merent from previously known species were found. To test whether these were hybrids between V. claviculata and V. barbellata , 11 morphological floral characters were recorded at seven populations and allozyme profiles of the three taxa compared. Principal component analysis on the morphological characters gave three distinct groups with minor overlaps. The first component axis reflects variation in overall size of the flowers, while the second component reflects variation in the size of the distal aperture of the labellum. Allozyme data revealed that the putative hybrids have a significant surplus of heterozygotes ( F IS = - 0.65) as expected in a F 1 generation. Both data sets support the hypothesis that the individuals are hybrids, which is further augmented by interspecific pollination experiments between the putative parental species. This is the first case of natural hybridization reported in the genus Vanilla .  相似文献   

15.
The panurgine genus Plesiopanurgus is redescribed and illustrated, and its relationships are discussed. A second species is described from a unique male from E. Turkey. The generic placement of some Arabian Panurginae is considered, and the genera occurring in southern Africa are listed.  相似文献   

16.
Historical relationships were inferred for the oriental lizards of the genus Takydromus Daudin 1802 (Lacertidae) on the basis of DNA sequences. Of the 17 species currently recognized for the genus, 13 species represented by 42 specimens from 29 localities were examined. Maximum-likelihood and maximum-parsimony analyses of data for 829 aligned sites from parts of the mitochondrial 12S and 16S rRNA genes yielded relationships that, while showing no substantial discrepancy with each other, were strikingly different from a currently prevailing phylogenetic hypothesis from a parsimony analysis of morphological characters. Based on the results of these molecular analyses, supplemented by results of the morphological analysis that offered robust evidence for positions of two additional species ( T. khasiensis and T. sylvaticus ), the following interrelationships were hypothesized as the most preferred phylogeny: ( kuehnei ( sexlineatus khasiensis ))( tachydromoides (( smaragdinus ( sauteri ( dorsalis sylvaticus ))) ( amurensis ((( formosanus wolteri ) hsuehshanensis )( toyamai ( septentrionalis stejnegeri )))))). These interrelationships indicate: (1) invalidity of Platyplacopus Boulenger 1917 , which was recently resurrected as a subgenus of Takydromus on the basis of the morphological analysis; (2) homoplasy in states of some morphological characters, such as green dorsal coloration, that were considered as synapomorphs of certain nodes in the morphological analysis; and (3) involvement of the genus in a series of vicariances in both the continental and insular parts of eastern Eurasia. Due to the paucity of available samples, phylogenetic status of T. intermedius and T. haughtonianus remain to be examined in future studies.  © 2002 The Linnean Society of London, Biological Journal of the Linnean Society , 76 , 493–509.  相似文献   

17.
A fourth species of the Holarctic Ilybius angustior complex, Ilybius minakawai n. sp., is described from the Island of Sakhalin in the Russian far east. Male genitalia are diagnostic within this species complex, although from body size and shape the new species cannot be separated from I. churchillensis Wallis from north Alaska and the Canadian low arctic. The small and narrow body characteristic of these two species represents an extreme of the cold climate form of the widespread I. angustior (Gyllenhal). Low variation within the studied large ribosomal and cytochrome c oxidase subunit I mitochondrial genes suggest that speciation events within the I. angustior-complex are fairly recent. In combination with known geographical ranges, the low genetic variation within this species complex suggest speciation within Pleistocene refugia including Beringia.  相似文献   

18.
In this paper, we revised the taxonomy of the Tuberculatus quercicola group, myrmecophilous drepanosiphine aphids that are associated with Quercus dentata and Q. crispula in Japan, based on morphometry and molecular phylogeny. This species group has been recognized as T. quercicola with some junior synonyms. Morphometric analysis of 11 morphological characters divided the group into three clusters: (i) the Q. crispula‐associated population; (ii) the central Hokkaido group of the Q. dentata‐associated population; and (iii) the eastern Hokkaido group of the Q. dentata‐associated population. Most parsimony and maximum likelihood analyses of the mitochondrial cytochrome oxidase subunit I COI gene indicated that samples of the T. quercicola group are separated, with high bootstrap supports, into two monophyletic groups that are associated with either Q. dentata or Q. crispula. However, no genetic differentiation was detected between the central Hokkaido group and the eastern Hokkaido group of the Q. dentata‐associated population. These results led us to conclude that populations associated with Q. dentata are genetically and morphologically distinct from those associated with Q. crispula, and thus they are in a full specific status. On the other hand, we treated the two local groups of the Q. dentata‐associated population as local races based on morphology. We formally redescribed the Q. crispula‐associated and Q. dentata‐associated populations under the names T. quercicola and T. macrotuberculatus stat. rev., respectively.  相似文献   

19.
呼晓庆  杨兆富 《昆虫学报》2019,62(6):720-733
【目的】揭示中国草地螟Loxostege sticticalis不同地理种群的遗传分化程度。【方法】采用PCR技术扩增中国西北和华北地区草地螟11个地理种群的线粒体 COI, Cytb和COII基因序列,基于其序列变异及单倍型贝叶斯系统发育树和单倍型网络图分析,探讨不同地理种群间的遗传距离、分子系统发生关系及遗传分化程度。【结果】草地螟11个地理种群的线粒体 COI, Cytb和COII基因序列分别有24, 12和69个变异位点(分别占总序列的3.6%, 2.7%和8.8%),检测到的单倍型分别为22, 14和16个,单倍型多样度(Hd)分别为0.7600, 0.5842和0.7341,核苷酸平均差异度(K)分别为1.704, 0.752和3.997,不同单倍型间的遗传距离平均值分别为0.004, 0.005和0.013。总种群的Tajima’s D和Fu’s Fs值皆不显著,表明草地螟不同地理种群间的遗传分化不明显,群体大小稳定。根据各地理种群的单倍型建立的系统发育树和单倍型网络图表明,各单倍型散布在不同的地理种群中,无明显的地理分布格局。【结论】草地螟各地理种群的遗传距离与地理距离间不具有显著的相关性,其遗传分化不明显。  相似文献   

20.
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